Zika causes far more damage to babies' brains than we originally thought

One of the images of the babies who were likely infected with Zika while in the womb. Radiological Society of North America There's still a lot we don't know about how Zika affects babies whose mothers contracted the virus while they were pregnant.

But a new study published Tuesday in the journal Radiology gives a glimpse of what babies' brains look like right toward the end of the pregnancy, as well as after the babies are born.

It's the most complete series of brain scans and ultrasound images of babies infected with the Zika virus, and the intent is to share the images to show all the ways Zika manifests in the brain, and what doctors should look for.

One thing the study makes clear is that the effect the virus has on infants' brains is complex and varied — and likely does not stop with the microcephaly that Zika has been known for. The scans suggest that some of the cognitive issues that Zika may trigger could show up much later than microcephaly, which is characterized by an abnormally small head and can be diagnosed right at birth.

While the new study is preliminary, the findings indicate that even a baby that appears normal at birth may have issues later.

"It's not just the small brain, it's that there's a lot more damage. The abnormalities that we see in the brain suggest a very early disruption of the brain development process," Dr. Deborah Levine, study author and professor of radiology at Harvard Medical School told The New York Times.

The researchers looked at 17 babies who were confirmed to have a congenital Zika infection, as well as 28 babies who were presumed to have contracted the infection. The researchers took scans of 31 of the babies before they were born, and all of them while they were newborns.

Here's what one of the MRI scans looked like, going from bottom to top:

Radiological Society of North America

The scan shows just how much fluid is packed in the brain, housed in the brain ventricles, The Times reports. These fluid-filled ventricles can be detrimental to the brain, and, because the brain appears swollen, the Zika virus infection could be missed because it doesn't have the same appearance as a baby with microcephaly.

The report, though based on a relatively small number of babies, is one of many that are piecing together exactly what congenital Zika infections can do to infants.

In April, the CDC confirmed that Zika is a cause of microcephaly. Often, babies born with abnormally small heads suffer from underdeveloped brains and other serious complications including vision problems. And an August study reported for the first time a link between Zika and arthrogryposis, a severe joint condition that's present at birth.